Originally founded by Pope Julius I, Santa Maria in Trastevere was the first church of St. Mary in Rome. Pope Innocent II ordered a new building on the site in 1140, and despite various alterations, it preserves its original medieval spatial appearance.

Shown in this model are the ceilings of the large central nave, the transept, and the semi-circular apse. The apse half-dome contains 12C mosaics.